A surface vehicle is a device that transports itself and a payload from place to place on the surface of the earth or other celestial body. Such vehicles can lose their mobility when encountering obstacles: positive obstacles which stick up from the average surface, such as logs, boulders, fences; negative obstacles such as holes, ledges, or ditches; and non-supportive surfaces such as rivers, ponds, or swamp muck. The inventors of the present invention have recognized that it would be desirable to have a surface vehicle which is not limited by such obstacles.
Prior art vehicles, such as motorcycles, are capable of overcoming obstacles; however, they require a ramp to impart a vertical component of velocity. This is impractical for free roaming vehicles for which it is desirable to overcome any obstacle encountered regardless of the presence of a ramp.
A prior art vehicle capable of imparting a vertical acceleration to the vehicle is a low rider, in which hydraulic cylinders are energized to cause the vehicle to rise and fall. There are several disadvantages of a low rider vehicle for the purpose of traversing an obstacle. The low rider does not provide sufficient acceleration to cause the vehicle to leave the ground an appreciable distance with a single actuation of the hydraulic cylinders. Instead, the cylinders are bounced at a resonant frequency to cause the vehicle to attain a significant vertical height with multiple actuations of the hydraulic cylinders. Such operation does not allow a low rider vehicle to clear an obstacle. Additionally, the control of the hydraulic cylinders is controlled remotely by a human operator. Moreover, the low rider is not adapted to provide significant vertical acceleration when the vehicle is translating on the ground. Instead, the highest vertical heights are achieved when the vehicle is not translating. Yet another disadvantage for the low rider in overcoming a positive obstacle is that the wheels are actuated in a downward direction to cause the vehicle to accelerate upward. With the wheels at their lowest extent possible, they would be the limiting factor for such a vehicle in clearing a positive obstacle.
Rockets and jet propulsion are used to generate vertical acceleration in known devices. However, both require a large amount of energy to provide the acceleration. Although they might be used to clear one or a few obstacles, they are impractical for clearing multiple obstacles that a vehicle might encounter simply because the fuel needs are too great.